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Oct. 8, 1929. E C, RENE ET AL 1,730,569

APPARATUS FOR EXTRACTING VALUES FROM COAL AND LIKE MATERIALS ffarageOct. 8, 1929. F. c. GREENE ET Al.

APPARATUS FOR EXTRACTING VALUES FROM COAL AND LIKE MATERIALS Filed July5. 1919 4 SheetS-Sheet 2 4 Sheets-Sheet Filed July 5. 1919 F. C. GREENEET AL APPARATUS FOR EXTRAGTING VALUES FROM COAL AND LIKE MATERIALS Oct.8, 1929.

Oct. 8, 1929.

Ec. GREENE ET AL APPARATUS FOR EXTRACTING VALUES FROM COALAND LIKEMATERIALS 4 Sheets-Sheet 4 Filed July 5. 1919 Patented Oct. 8, 1929UNITED STATES PATENT OFFICE FRANK C. GREENE, OF DENVER, COLORADO, ANDIRVING F. LAUCKS, 0F SEATTLE, WASHINGTON, ASSIGNORS T0 OLD BEN COALCORPORATION, OF CHCAGO, ILLNOIS,

A CORPORATION OF DELAVJARE APPARATUS FOR EXTRACTING VALUES FROM COAL ANDLIKE IYIATERTALS Application led July 5, 1919. Serial No. 308,774.

Coal has been defined by one well known authority (V. B. Lewes, inCarbonization of Coal) as being a conglomeration of humus and itsdegradation 'products with resinic bodies and their derivatives. We havedis covered that at relatively low temperatures and properly controlledpressures these resinic bodies and related hydrocarbon compounds foundin such coal and like material can, with proper handling, be removed bydistillation and valuable products recovered. The result is theproduction, or rather recovery, of a larger quantity of aromatic oils,i. e. hydrocarbons of the benzene series, than has heretofore beenaccomplished or thought possible.

The object of the present invention is the provision of a suitableapparatus for carrying out a distillation process of the character justindicated and more speciically described in our copending applicationSerial No. 218,452, it being understood that such apparatus is notnecessarily limited to any such particular field of use, but may beemployed generally in the carbonization of materials such as coal andlike carbonaceous ma terial. The apparatus accordingly includes meansfor handling the raw material, means for retorting the same, means forwithdrawing and condensing the volatile matter given off duringitheretorting, as also means for withdrawing the charred residue which, as aresult of the treatment to which it is subjected, has been found toconstitute a fuel of superior value.

To the accomplishment of the foregoing and related ends, our invention,then, consists of the apparatus or mechanism hereinafter fully describedand particularly pointed out in the claims, the annexed drawings and thefollowing description setting forth in detail one approved constructionof apparatus, such disclosed construction, however, constituting but oneof the various mechanical forms in which the principle of the inventionmay be used.

In said annexed drawings Fig. 1 is a plan view, more or lessdiagrammatic. in character, of the layout of a plant equipped for thedistillation or retorting of carbonaceous material embodying our presentimprovements; Fig. 2 is a front elevation of such plant; Fig. 3 is aside elevation of the same as viewed from the left in Fig. l; Fig. 4: 1sa side elevation of the preferred construction of the retort which formsthe central feature of such plant; Fig. 5 is partly a top plan view andpartly a section at the break in Fig. 4 of several such retorts alinedin series and the furnace in which they are mounted; Fig. 6 shows adetail of such furnace; and Figs. 7a and 7b illustrate a verticalsection of the retort, or rather of a pair of such retorts looking` inthe direction of the alined retorts of Figs. l and 5, the plane of thesection being different in the two retort-s respectively, and the secondsuch figure being the lower continuation of the first.

l/Ve do not concern ourselves with the contlicting theories nor theaccepted theories relating to the constitution and thermal decompositionof various coals. `We have found that by our apparatus the thermaltreatment given the coal results in an increased yield of aromaticcompounds compared with the aliphatic compounds over what has beenheretofore obtained.

We have found that not only is it necessary to use low temperatures andlow pressures in order thus to obtain these `valuable constituents ofthe coal, but that the limits of temperature wit-hin which these desiredhydrocarbons may be vaporized without being decomposed or degraded intoothers of lesser value, are fairlv narrow. Wie have likewise found thatto successfully apply the proper temperature and pressure, the size ofthe particles of the material being treated, as well as the degree oftheir dispersion, must be regulated, in order that each particle mayobtain a uniform temperature throughout and that particles in the samevicinity in the retort may be uniformly heated to substantially the samedegree.

We have also found that if the vapors are allowed to linger in atemperature Zone as high as that required to setthem free, chemicalchanges will in a measure proceed, and so we accordingly provide for theimmediate removal of the vapors away from the region of their formationor heated Zone, in order that they may undergo the least possibledegradation.

In the apparatus illustrated in the drawings, vertical retorts ofgeneral cylindrical form are utilized in which to heat the coal or likematerial. The latter is desirably finely ground, the minimum limit ofiineness being determined by the conditions attending the handling of apowdered material of this character, both in conveying it to the retortand in passing it through such retort. riChe maximum limit is determinedby the speed of the progress of the particle into higher temperaturezones, the temperature of such zones, and the resulting thermalconductivity ofthe particle which will vary according to the volatileconstituents contained therein. We have in practice found it feasible towork with particles from one-fortieth inch to one-half inch in diameter.The manner in which the material is reduced to the requisite degree offineness forms no part of the present invention, and need not bedescribed other than to state that suitable crushing mechanism will beprovided for this' purpose.

In said drawings, Figs. 1, 2 and 3 illustrate a preferred layout ofplant, in which the carbonizing retorts are employed. As there shown,the coal is first fed through a erusher 1, then dried in a rotary drier2 and afterwards ground to the desired degree of fineness by a mill 3,and carried by means of an air conveyor 4 to the top of the carbonizingtower 5, which consists of a series of paired retorts 6 arranged side byside as shown in Fig. 1, the interior construction of such retorts beingshown in Figs. 4, and 7. The retorts are supported within a suitablefurnace chamber, or rather chambers, 7. arranged in pairs, there'being alongitudinal series of such pairs of chambers, within which the retortsare disposed., respectively, such chambers being of any desired length,and as many pairs thereof being provided as the size of the operationmay make necessary. The retorts are preferably suspended from theirupper ends in the furnace chainbers so as to permit free downwardvariable expansion. The combustion chamber 8 from which the gases forheating the retorts are derived, is conveniently located between the twoseries of furnace chambers, such heated gases entering the latter at thebott-om through openings 9, as shown in 7b, and escaping at the topthrough openings 10 into a waste heatflue 11 which, in connection withan exterior duct 11a, conducts the spent gases from the chambers to thedrier Q, so as utilize the waste heat as fully as possible.

A lighting hole 12 leads from the exterior of the one furnace chamber tosaid combustion chamber for igniting the combustible mixture of air andgas supplied to the burner 13 therein from air and gas mains 14 and 15respectively. The latter are simultaneously controlled by means ofvalves 16 and 17 operated by means of suitable levers and a connectingrod 18, likewise extending without the wall of the furnace chamber. Ahole 19 is also provided in the wall of each chamber near the bottom ofthe latter for the insertion of a pyrometer (not shown) in order todetermine the temperature within such chamber.

Each retort 6, proper, consists of a vertically disposed tube,preferably of iron, which extends the length of the furnace, such tubebeing provided with external ribs 2O disposed in a helical fashion aboutthe same, that cause the combustion gases, as they pass upwardly throughthe furnace chamber, at the same time to circulate about the retort, andso insure the thorough and, uniform heating of all portions of the same,and large absorption of heat.

Within each such tubular retort is rotatably mounted a second tube 21,the upper end of which projects beyond the upper end, not only of theretort proper, but of a head 22 that surmounts the latter. Inner tube 21is provided externally with a spiral rib or flange 23, that extends fromits lower end to a point adjacent the upper end of the retort, and is ofa width to substantially span the annular space left between the tubeand retort. The relative diameters of the retort tube 6 and the rotarytube 21 are such that the annular space between them is relativelynarrow, the reason for this appearing more fully hereinafter. Said innertube is also provided, between the flights of such spiral rib, with aseries of perforations 24, that permit and afford free communication forvapors to quickly escape from the annular spa-ce between the retortwalls and such tube, to the interior of the latter. The upper end ofeach such inner tube is closed by a vacuum seal consisting of acounter-weighted valve 25, that is held to its seat by the vacuum withinthe tube produced, as will be presently described, but is adapted toopen automatically upon the breaking of such vacuum. Driving means forrotating each tube 21 are likewise connected with the upper endsthereof, such means consisting of a ratchet wheel 26 operated by a pawl27 on an oscillatory arm 28 the free end of which engages a camk 9.9 onthe main drive shaft 30 of the apparatus. To reduce power required forrotating these tubes, a suitable ball-bearing 31 is employed under theupper bearing-flange 32 in the head 22.

The upper portion of the head 22, that surmounts each retort is sealedoff 'by means of a suitable flange `from the lower portion thereof,which latter freely communicate with the retort, that is, with theannular space between the inner tube 21 and the relll) tort walls; whileabove the partition, provided by such flange, other perforations 36 areformed in said inner tube, by means of which its interior is connectedthrough a duct 37 with a vapor main 38, that is placed under suction bymeans presently to be described,.and the desired degree of vacuum thusprovided within the tube. A valve 39 isprovided in each duct 37 forclosing the saine simultaneously ywith the opening of a discharge gate4() at the bottom of the char chamber 41, and vice versa, as will alsobe presently described.

Connected with each head 22, below the partition therein just referredto, is a duct that is adapted to receive the finely ground coal, or likematerial, from a conveyor trough 46 and supply the same to the upper endof the retort. The rate of feed is controlled by means of a screw 47located intermediate between the ends of such duct, this screw beingconnected to be operated from the drive shaft 30 by means of a chain 48and suitable variable speed gearing 49, which need not be described indetail. A. valve 50 for closing the duct 45 is also provided, such valvebeing interconnected with the valve 89 in the corresponding vapor ductby a link 51.

The lower end of each retort communicates with, and discharges directlyinto, the char chamber 41 above referred to, that is located directlytherebeneath. The lower end of such char chamber in turn is adapted tobe sealed by means of thel discharge gate 40, likewise referred toabove, that is pivotally attached at one side of the chamber andnormally held closed by means of a swinging yoke adapted to engagetherewith through the medium of a roller 56 and tightly close the sameas it is swung from the position indicated in dotted lines, to thatindicated in full lines, in Fig. 7b. In order always to insure a tightclosure and to prevent the charred material from getting caught betweenthe gate and the lower end of the chamber 41, such end is formed with adownwardly directed encircling groove 57 into which the beveled edge 58of the gates is adapted to fit7 all as clearly shown in the same figure.Y

As previously indicated, the operating means for this discharge gate,specifically the yoke 55 just described, is interconnected with thevalve 39 in the corresponding vapor duct 37 at vthe upper end of theretort, the rod 59, that serves for this purpose, extending well abovethe retort and serving, when raised, not only simiultaneously to closethe discharge gate in question and to automatically open the valve inthe vapor duct, but also, through the link 51, to open the valve in thefeed duct, and, through the medium of a projection 60 on its upper end,to automatically lift the weighted arm of the valve 25 that closes,

' or seals, the upper end of the-.inner tube of the retort. Theoperative connections between rod 59 and the yoke 55 include atransverse bar 61 secured to the lower end of said rod, the respectiveends of which are held in grooves or slots 62 formed in a comple mentarypair of segmental plates 63 carried by said yoke, one on each side.These slots, it will be observed, comprise two communicating arcuateportions that have the axis 64 of the yoke for their common center, butthe uppermost such portion, in the position of parts shown in Fig. 7b,is disposed at a slightly greater radial distance from such axis thanthe other. There is also an offset or ledge 65 formed on the side of thecharchamber 41 adjacent the lower end of said rod 59, adpated to receiveand support a roller 66 mounted on the aforesaid bar 61, when the rod isin its upper or raised position.

lVhen the yoke 55 is swung to the left in the figure of refernce, suchmovement does not initially have any effect on the rod, the portion ofthe respective slots 62, then in engagement with bar 61, retaining suchbar in position where said roller 66 rests on ledge 65. Further swingingmovement of the yoke, however, serves simultaneously to release the gate40 and to shift said roller 66 olf the ledge in question, so that therod 59 is free to drop and thereby actuate the several valves connectedwith its upper end. A full range of movement of the rod in thisdirection is insured by the engagement of the other portion of slots 62with the bar. Upon reverse swinging movement of the yoke, as soon as themidpoints in slots 62 are brought into Contact with said bar, the latteris lifted, thereby elevating the bar, until the roller 66, which ridesthe while on the lateral face of offset 65, reaches the upper face ofthe latter. Then the lower portion of slots 62 pull said bar inwardlyand cause the same to seat as before on top of the offset or ledge. Aspring buffer 67 is mounted alongside chamber 41 in position to engage astop 68 on rod 59 in the lowered position of the latter, as will bereadily understood, while a turnbuckle 69 in said rod permits of itsadjustment as to length.

ln addition to provision being made for the withdrawal of vapors fromthe interior of the inner tubes of the several retorts, a second vapormain 7 O is disposed alongside the lower ends of the series of retortsand is connected with the upper portions of the correspondingchar-chambers 41 through suitable ducts 71 that are controlled by valves72 operatively connect-ed with the rods 59, just as are the valves inthe upper ducts. lVe also provide in this connection a piston orstopper` 75, that is adjustably litted within the lower end of eachinner tube, being of eXpansible c0nstrucrod caused to frictionally seatitself in such selected location. The location of this piston, orstopper, will obviously determine the point at which, in the descent ofthe material through the retort,` the vapors given off therefrom areconducted upwardly and collected in vapor main 38, and the point atwhich the vapors thus given off are conducted downwardly and collectedin the lower vapor main.

rlhe charred or carbonized residue, upon being` discharged from chambers41, is received and collected in a receptacle of adequate size, the sidewalls of which converge towards a troughdike depression 8O in which anendless belt 81 or other conveyor operates to transfer this material toany desired point. As shown in Fig. 1, this material, after beingconveyed to the further, i. e. right-hand, end of the series of retortsor retort tower, is carried by another conveyor 82 to a storage bin 83.

The vapor mains 38 and 70, with which the interiors of the severalretorts and the charchambers are respectively connected as hereinbeforedescribed, lead to vacuum pumps 84 in the condensing and distillingplant 85 (Figs. 1 and 2), the connections 86 for said main 38 onlyappearing. Here, after condensation, the products are received insuitable tanks or containers, thereafter to be further treated toseparate the various constituents with such degree of refinement as maybe desired in the particular case.

By locating the crushing and drying plant, the condensing andredistilling plant, and the storage bin for the carbonized residue, allon the same side of the retort tower 5, a very compact arrangement isrendered possible, facilitating the handling of the material in itsvarious stages andenabling a single track 87 to serve both the receivingand discharge ends of the plant. Moreover, as indicated in dotted linesin Fig. 1, by carrying projections of ducts i and 8G as well as of theconveyor 82, a plurality of series of retorts or retort towers 5 can beconnected up in the same fashion as the one shown in full outline withthe several parts of the plant.

VHaving regard to the illustrative apparatus just described, the mannerof operation, exemplifying our improved method or process for extractingvalues from coal and like material, may now be briefly set forth. Thesuitably crushed, and preferably dried, material is received in theupper end of the retort, or rather into the upper end of the annularspace between the rotatable inner tube in such retort and the inner wallof the latter, from the conveyor through the feed duct 45. The feedscrew 47 in such duct serves to regulate the rate of feed.

The rate of feed is regulated so as to supply the material in a streamof suitably adjusted quantity on the spiral flange 28 carried by therotating inner tube. The material, in other words, is passed through theretort in the form of a relatively thin vertical (in this case) layerresting on this flange, the particles not only being sufficient-lysmall, but so dispersed as to be all practically uniformly heatedthroughout. Owing to the heated contact area of the retort wallpresenting sufficient frictional resistanceto the thin stream of coa-l,or like material, to cause such stream to rotate in its passage alongthe heated surface, a churning action results which tends to continuallypresent fresh surfaces, or to prevent the continuance of the samesurfaces, to the heated contact area. This action is im.-l portant astending to expedite and facilitate the evolution of vapors and theirready withdrawal, constituting an effect similar to dispersion. Theannular space containing the material being relatively narrow, ashereinabove stated, contributes not to the frictional resistance of thematerial adjacent the retort wall, but to the amount of rotation orcirculation produced in the stream of coal by reason of such frictionalresistance. It is clear that any particle of material resting on theflight of the rotor tends to advance downward through the retort only bythe action of gravity, and that the frictional resistance between theparticle and the rotor flight tends to carry the particle in a circularpath about the axis of the retort. Then any particle contacts thestationary outer wall, the friction therewith holds it back in itscircular orbit and advances it downwardly through the retort. So with alarge number of small particles on the flight, those adjacent the retortwall advance more rapidly and their place is taken by particles whichwere previously not in contact with the outer wall. Thus the churningaction is produced by the resulting movement of particles into and outof contact with the wall. And it is important in taking advantage ofthis churning action, that the width of the annular space be small tobring all the particles more frequently into contact with the heatedWall in the course of the churning, thereby distributing the heat byconvection and conductance. The mode of supplying the heated gases tothe furnace chamber, taken in conjunction with the arrangement of ribs20 on the retort insures an equable heating effect and absorption ofheat in all horizontal.

"planes, although the heating gases `are of course hottest in the lowerportion of the furnace chamber and gradually cool off-as they ascendvertically, due to the absorption of heat by the material as it passesdownwardly through the retort. A higher temperature may be used in thelower section of the retortto drive off' all volatile matters from thematerial being treated, and thus approximate known coking processes.

Additional burners may be applied to the retort 1 at various'pointsalong its length to provide heat to a degree commensurate with theabsolute pressure, fineness and composition of the coal or likematerial, and speed of operation employed, and with the degree ofexpansion of evolved vapors. A relationship exists between these, andpossibly other elements of operation, which elements when properlyadjusted, or synchronized, constitute the process resulting in maximumroduction of evolved condensible vapors o the valuable aromatic series.

External heating temperatures may thus be varied, as may pressures,speed, ineness. Such temperatures we have found may vary from say 800o Fahr. to 12000 Fahr. although these limits are not fixed. Apparently thelimiting element of this opera'- tion is the reduction of pressure to aperfect vacuum, which, while practically unobtainable, is thedesideratum. Provision is made for tightly-sealing the retort at bothends, and, by means of suitable suction apparatus connected with the twovapor mains, we reduce the pressure within the retort to the lowestpossible degree, any increase in the pressure towards atmosphericresulting in a corresponding decrease in the amount of aromatic oils inthe products obtained.

The suction thus employed in order to reduce the pressure within theretort is simultaneously effective to with-draw the vapors, as fast asthey are formed, away from the heated zone; that is, they are suckedthrough the apertures in the inner vapor tube and thence to suitablecollecting and condensing apparatus, such vapor tube being found to havea considerably lower temperature under these conditions, by at leastseveral hundred degrees, than the external heating temperature.

lVherc it is desired to drive off all the volatile constituents possibleby applying to the lower portion of the retort a higher range oftemperature than that indicated above, the use of a piston or stopperwithin the vapor tube is desirable, since in this way it is renderedpossible to segregate the so-called lean gases resulting from this stagein the process, from the vapors, rich in aromatic hydrocarbons, whichare evolved in the initial or main stage of the process. In other words,by the means in question we are enabled to ef'- fect a fractionaldistillation of the volatile constituents in the original material. Suchfractionating may be carried further if desired, for we have found that,by proper manipulation of the temperatures within the retort and vaportube, the vapors given off may be made to consist more largely of eitherlowboiling or high-boiling compounds as desired.

Other modes of applying the principle of our invention may be employedinstead of the one explained, change being made as regards the mechanismherein disclosed, provided the means stated by any of the followingclaims or the equivalent of such stated means be employed.

We therefore particularly point out and distinctly claim as ourinvention 1. ln apparatus of the character described,-

the combination with a furnace; of a vertically disposedcylindricalretort located within such furnace; a perforated tubular memberrotatable within said retort and leaving a relatively narrow annularspace, the upper end of said member projecting above such retort; meansadapted to supply material to be treated to the upper end of such space,said member being provided with spiral ribs adapted to regulate thepassage of such material through such space; suction connections forwithdrawing vapors from the upper and lower ends of said member,respectively; a valve adapted to close the upper end of said memberunder the suction thus maintained therein; and means adapted tosimultaneously control said suction connections and said valve.

2. ln apparatus of the character described, the combination with afurnace; of a vertically disposed cylindrical retort located within suchfurnace; a perforated tubular member rotatable within said retort andleaving a relatively narrow annular space, the upper end of said memberprojecting above such retort; a char-chamber forming a continuation ofthe lower end of said retort; a hollow head surmounting the upper end ofsaid retort and surrounding said member, said head having a transversepartition; means adapted to supply material to be treated to such headbelow such partition; and suction lines connected with said head abovethe partition therlein and with said char-chamber, respective y.

3. In apparatus of the character described, the combination with afurnace; of a vertically disposed cylindrical retort located within suchfurnace; a perforated tubular member rotatable within said retort andlea-ving a relatively narrow annular space, the upper end of said memberprojecting above such retort; a char-chamber forming a continuation ofthe lower end of said retort; a hollow head surmounting the upper end ofsaid retort and surrounding said member, said head having a transversepartition; means adapted to supply material to be treated to such headbelow such partition; a transverse partition at an intermediate pointwithin said member; and suction lines connected with said head above thepartition therein and with said char-chamber, respectively.

4. ln apparatus of the character described, the combination with afurnace; of a vertically disposed cylindrical retort located within suchfurnace; a perforated tubular member rotatable within said retort andleavinga relatively narrow annular space, the upper fil end of saidmember projecting above such retort; a char-chamber forming acontinuation of the lower end of said retort; a hollow head surmountingthe upper end of Said retort and surrounding said member, said headhaving a transverse partition; means adapted to supply material to betreated to such head below such partition; a transverse partition at anintermediate point Within said member;

' suction lines connected With said head above the partition therein andWith said charehamber, respectively; valves in said Suctionlines;another valve adapted to close the upper end of said member under thesuction thus maintained therein; and means adapted to simultaneouslyControl said valves.

Signed by me7 this 28 day of June, 1919. FRANK C. GREENE. Signed by me,this 24 day of June, 1919. IRVING F. LAUCKS.

